* Centralise the generation of help for root command

Add argparse2help.py, add root-argparse.py, delete the old help of root, add the cmake commands needed to generate the header containing the command line options help and to generate manual page for the root command.

The python file argparse2help.py can be called with the root-argparse.py and the output name as arguments. This call will generate the header file if the output has an extension ".h" and will generate the manual page if the extension is ".1"

* Centralise the generation of help for the rest of the commands

Add cmake changes to generate headers and manual pages for rootcling hadd and hist2workspace
Delete old man pages of hadd and hist2workspace
Add commented out generation of man pages for python commands, we need to add a dependency before uncommenting them out
Add hadd rootcling hist2workspace argparse modules

* make the path compatible with windows

* review modifications

* add dependency on the input and the generation script of man pages

* remove installation of headers

* Update CMakeLists.txt

It makes no sense to generates man pages on Windows. Windows does not have the `man` command.

* Update argparse2help.py

* Update argparse2help.py

* Update argparse2help.py

* Update hadd.cxx

haddCommandLineOptionsHelp.h was not included for windows

* Update root-argparse.py

add the option --version

* Update argparse2help.py

simplified version (Thanks Bertrand !)